Heat exchange apparatus



March 21, 1939. R. DIETZE HEAT EXCHANGE APPARATUS 2 Sheets-Sheet 1 FiledOct. 2, 1937 March 21, 1939. R. DIETZE 2,151,087

HEAT EXCHANGE APPARATUS Filed oct. 2, 1957 2 sheets-sheer 2 PatentedMar. 21, 1939 y HEAT EXCHANGE APPARATUS Reinhold Dietze.- Goeschwitz,Germany Application October 2', 1937, Serial No. 167,064

Y InGermany January 5,1937

9 owns. (ci. zes-azi This invention relates' to heat exchange apparatusrand more particularly to improvements in rotary kilns for the burning,calcining, roasting, and sintering oi various kinds of materials.

v5 It is the principal object of the invention to increase the outputand improve the eiliciency of kilns to the end that operatingexpenses'may be reduced and the product of the kiln rendered .kiln Suchan arrangement has never been adopted in practice, however, since' theimprovement in efiiciency of the kiln resulting therefrom mdsnegligible. Failure of such walls to assist in the exchange o! heat canprobably be .explained by the fact that there is little tendency for thehot gases to circulate within and about the kiln or to break away fromthe intermediate wall; conseg quently only a relatively small portion ofthe hot gases actually contacts this wall.

In accordance with the present invention it is proposed to provide aplurality of walls or partitions interiorly of the kiln, such partitionsextending generally longitudinally of the kiln and being spaced in thedirection of the length thereof, the successive partitions being rsodisposed as to occupy different positions with respectto the axis of thekiln. For example, in one arrangement, the partitions may bediametrically disposed, the successive partitions being arranged inincreasingly greater angular relation with the iirst partition, so thatthe whole series of partitions forms in eiect an interrupted helix. Itwill be apparent'that with such a construction diierent portions of thestream of hot gasare contacted by the successive partitions. Again,there -isa tendency, when a helical arrangement of the partitions isemployed, to cause the hot gases to follow a generally helical path, andthe swirling motion thus set up results in the contacting of thepartitions and the material being fed through the kiln by a greater`volume Vof the hot gases. 50 It is also found that a kiln equipped withlongitudinally spaced and oiset, staggered or helical partitions ensuresthat the hot gases are brought into contact with the whole of thematerial passing through the kiln and not only with the sur- 1 :lacelayer thereof, the partitions being eectivetoagitatethematerialandtobreakitupand shower it down through the cimentof gas.

It has been found in the application of the principles of the instantinvention to a cement kiln, that it is not only possible to eiect an in-5 crease in the kiln output of 18% and a fuel saving of 14%, but thatthe formation of deposits on the wall of the kiln, commonly referred toask rings, is avoided, these deposits normally resulting from thefailure of the kiln to effectively dry. 1o preheat, and otherwisecondition the material before it enters the principal sintering zone.

Further objects and features of the invention will be apparent from thefollowing description taken in connection with the accompanying draw- 15ings, in which Figure 1 is a longitudinal sectional view of a rotarykiln constructed in accordance with the present invention;

Figure 2 is a transverse sectional view taken 20 substantially on theline 2-2 of Figure 1;

Figures 3, 4, and 5lare transverse sectional views corresponding toFigure 2 and illustrating modified forms of partition; Y

Figure 6 is a longitudinal sectional view of a 25 kiln illustrating afurther modiiled form of partition;

Figure 7 is a horizontal section on the line 1-1 of Figure 6; and

Figure 8 is a transverse sectional view on the 3g line 8-8 of Figure 6.y

.Referring first to the form of the invention shown in Figures 1 and 2,numeral I0 indicates a Y rotary kiln of any conventional type, means forfeeding material to be treated, forexample ce- 35 ment, into one end ofthe kiln being indicated at Il. At the discharge end of the kiln a fuelnozzle I2 may be provided, whereby hot gases may be caused to flowthrough the kiln in a direction opposite to that in which the materialis 40 moved. It will be appreciated that the details of these elementsform no part of the instant invention and that the construction of thekiln and its accessories may be modified as desired to suit the materialuncergoing treatment and the nature of the process applied thereto.

As hereinbefore indicated, the invention re sides in the provision of aplurality of walls or partitions I5 which are diametrically or o wisechordaily disposed within the kiln I0, these partitions being spacedlengthwise of the kiln and being angularly related or otherwise oiisetas bly arranged at a constantly'increasing angle so as to define agenerally helical path, a swirling motion being thereby imparted to thehot gases as and are uniformly spaced and angularly disposed.

It will nevertheless be appreciated that considerable modication of thisarrangement maybe eected without sacricing the advantages derived fromthe invention. For example, each partition may be formed as indicated atI6 in Figure 3, to provide a concave suri'acev I1 on either sidethereof. Alternatively, a plurality of partitions may be disposed incontiguous relation to provide more than two passages for the hot gases.Reference is .made in this connection to Figure 4 in which the kiln Il!is provided with partitions I8 and I9, each of which may be arcuate intransverse section, these partitions defining chambers 20, 2|, and 22.

In Figure 5 of the drawings isillustrated a partition 25 of which thelateral surfaces are ribbed or corrugated as at 26 to form projections fand depressions, this type of surface facilitating the transfer of heatinto the partition and effecting greater agitationof the material as itpasses through the kiln. If desired the partitions may be apertured topermit pasage of gas through as well as along the same.

The construction shown in Figures 6 to 8 is quite similar tothatillustrated in Figures 1 and 2, with the exception that each of thepartitions is twisted or formed generally helically, this constructionserving to increase the tendency of the hot gases to rotate, swirl, orfollow a helical path in passing through the kiln, with resultingincrease in efficiency.

In order to aid `in an understanding of the invention, specific languageis. employed herein to describe the several embodiments thereofillustrated in the drawings. It will nevertheless be appreciated thatvarious further modiiications and alterations ofthese structures arecontemplated such as fall within the spirit and scope of the inventionas defined in the appended claims.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. In heat exchange apparatus, the combination with a rotary kiln, of aplurality of longitudinally spaced and generally lonlgtudinallyextending partitions disposed interiorly of said kiln,

transverse sections o! successive partitions defining increasing angleswith the ilrst partition to form in effect an interrupted helix.

2. In heat exchange apparatus, the combination with a rotary kiln, ofmeans for passing hot gas through said kiln, and means within said kilnfor deecting said gas to cause the same to describe a generally helicalpath within said hln.

3. A rotary kiln having a generally longitudinally extending helicalpartition therein.

4. A rotary kiln having a series of diametrically disposed, generallylongitudinally extending partitions therein, said partitions beinglengthwise of said kiln, successive partitions being arranged inincreasing angular relation to the frst'partition to form in effect aninterrupted helix, each partition being of generally helical shape.

5. In heat exchange apparatus, the combination with a rotary kiln, of aplurality of longitudinally spaced and generally longtudinally extendingpartitions disposed interiorly of said kiln, said partitions beingoffset with respect to each other as viewed endwise of the kiln, thelateral surfaces of said partitions being curved.

6. In heat exchange apparatus, the combination with a rotary kiln, of aplurality of longitudinally spaced and generally longitudinallyextending partitions disposed interiorly of said kiln, said partitionsbeing oifset with respect to each other as viewed endwise of the kiln,said parti- Y tions having openings therein .to permit passage of gastherethrough.

7. A rotary kiln'having a plurality of longitudinally spaced, chordalpartitions suppdrted at,

the lateral ends thereof on the kiln wall to aiford substantially freepassages for gas at each side thereof.

8. A rotary kilnhaving a series oi' diametrically disposed, generallylongitudinally extending partitions therein, said partitions beingspaced lengthwise of said kilnv and being supported at the lateral endsthereof on the kiln wall to afford substantially free passages for gasat each side thereof.

9. A rotary-kiln having a series of diametrically disposed, generallylongitudinally extending partitions therein, said partitions beingspaced lengthwise of said kiln, successive partitions being arranged 'inincreasing angular relation to the first partition to form in eifect aninterrupted helix, said partitions being supported at the lateral endsthereof on the kiln wall to aord substantially free passages for gas ateach side thereof.

RELNHOID DIETZE.

